This is my summary of the inventions I studied this week in lessons one hundred forty-one through one hundred forty-four. In lesson one hundred forty-one, I learned about the invention of the safety razor. Before the safety razor, shaving was expensive. It was an art, and it required much skill to do it properly. Besides, it took a lot of time and effort to properly sharpen the blade daily.

All this was changed when King Camp Gillette invented both the safety razor and the disposable blade at the same time in 1901. Gillette sold bottle tops and corks for a living. They were both bought only to be thrown away after one use, so Gillette decided he could do the same for razor blades. The safety razor, along with disposable blades, makes it much easier to shave, since you no longer need to go to a barber to do it.

In lesson one hundred forty-two, I studied the invention of the airplane. The airplane was invented in 1903 by Wilbur and Orville Wright. While flight wasn’t necessarily a new concept, it was uncontrollable; no one had found a way to steer when in the air. One person in particular named Otto Lilienthal got very close to inventing a way to fly, and he inspired lots of people.

Two of the people Lilienthal inspired were named Wilbur and Orville Wright. They picked up where he stopped and began making experiments. They used their knowledge from building bicycles and applied it to building airplanes, which led to the invention of the airplane in 1903.

In lesson one hundred forty-three, I learned about the invention of the vacuum tube. The vacuum tube was invented by John Ambrose Fleming in 1904. The vacuum tube makes a current that flows in only one direction, meaning it can convert AC power to DC power. DC power is most commonly used in electronics, which makes the vacuum tube very useful.

Last of all, lesson one hundred forty-four was about the invention of the Model T car. The first car had been invented in the 1870’s, but it was very expensive. More cars were invented after that, but none of them were affordable for average families. The Model T was the first affordable car, and it was invented in 1908 by Henry Ford.